Hijackthis scanned my computer, but I don't know which files to delete-can anyone help?

Moderator Edit: Moved topic to more appropriate forum. ~ Animal

Hello and Welcome to bleeping computer

I think you should use this, fairly simple self help, tutorial to get rid of Spydawn first.
Remove Spydawn

Changing the wrong things in that log can be a problem. We can worry about fixing the log later, if it is still needed.
Please let us know how it goes or if you've any further questions

Try using this BC Self-help Removal Guide:

http://www.bleepingcomputer.com/forums/topic81275.html

If that does not resolve your problems, then submit a HJT Log for our volunteer experts to review and help you clean up your computer. Instructions for log submittal can be found here:
http://www.bleepingcomputer.com/forums/topic34773.html

Regards.
John